Rotary abrading tools of the erasure type are well known and typically comprise a rotary driven annular disk made of an elastomeric material, commonly referred to as an “eraser wheel” or an “eraser disk.” Rotary abrading tools of the erasure type are used to remove adhesive material, such as paint and decals, from metal surfaces. An eraser disk is rotated at high speeds and pressed against adhesive material for removal. Eraser disks of this type tend to become deformed over time, and consequently, lose their efficiency. Therefore, eraser disks need to be replaced frequently, often during the course of completing a single project.
In U.S. Pat. No. 5,259,914, Fisher discloses a disk-shaped eraser unit with a flat disk embedded inside the eraser member. The disk has a central opening and two rim notches. When molding the rubber eraser member with the disk embedded, the rubber material will fill the two rim notches. A bolt having an elongated shaft extends through the central opening of the disk and is secured by a nut and washer. The elongated shaft extending from the eraser member is attached to a rotating drive means. As the eraser unit rotates against a workpiece, the outer periphery is worn down and renewed. Because of the minimal mechanical interlock between the embedded disk and eraser material, this system relies heavily on the sufficiently high adhesion between the embedded disk material and the sufficiently high strength of the eraser material to prevent the embedded disk from shearing loose and spinning freely within the eraser.
To overcome the problem of disk slippage that may result from the use of the invention disclosed in Fisher, the invention disclosed in U.S. Pat. No. 6,309,292, (Montabaur et al.) provides for a more extensive interlocking of parts between the eraser and the disk or hub that is connected to a tool. Montabaur et al. disclose a rotary tool for the erasure-type abrading of adhesive residues from metal surfaces, having an outer tooth crown of an elastomeric material mounted on a disk-shaped holder, which is rotatably driven and coupled to the latter by an inner crown. Attaching an eraser disk in this manner requires removing the crown prior to replacing the eraser.
However, as mentioned in Montabaur et al., eraser disks are not easily replaceable. The replacement of an eraser disk often involves detaching the hub or several pieces from the base tool. This complicated number of steps is not time efficient, especially when eraser disks need to be replaced frequently. In U.S. Pat. No. 6,136,143, Winter et al. recognize the need for frequent replacement of eraser disks. The invention in Winter et al. allows a user to replace the eraser disk without removing the hub, which the eraser disk is attached to, from its base tool. However, Winter et al. fail to disclose an eraser disk that is quickly replaceable. Rather, the eraser disk disclosed in Winter et al. is attached to the hub via complicated interlocking parts, and in the preferred embodiment, the eraser disk is molded to the hub. Attaching the disk in this manner takes added time and is an inconvenience for the user to replace the eraser disk.
Thus, there is a long-felt need for a rotary abrading tool assembly that is free from the drawbacks of earlier tools used for erasure-type abrading. In particular, there is a need for a device that provides for easier disk replacement without performing tedious and time consuming replacement procedures.